A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. The following notice shall apply to this document: Copyright(copyright) 1999, Microsoft, Inc.
The present invention pertains generally to user input arrangements for use with computer devices, and more particularly to input arrangements for use with hand-held computer devices.
Non-alphabetic languages, i.e., languages not based on the Roman alphabet, are often characterized by a relatively large number of characters. The English language features twenty-six letters that combine to form words. By comparison, the Chinese language features thousands of ideograms (called Chinese characters) that represent entire words; each character is formed from units known as radicals, of which hundreds exist. Due to the large number of characters in the Chinese language, many early approaches for inputting Chinese characters into computer systems involved large, unwieldy keyboards with many keys. Advances in Chinese computer technology have been accompanied by improvements in Chinese input approaches.
These approaches can be categorized into two types. One type is radical-based and involves mapping the set of radicals to the standard English keyboard. The other type involves the use of a phonetic scheme known as Pinyin, which has long been used to represent Chinese characters. In this Pinyin-based scheme, each Chinese character is assigned a Romanized representation derived from a phonetic spelling of its pronunciation. The Pinyin representation of a Chinese character, therefore, can be broken down into phonemes identical to the Roman alphabet. Additionally, tonal information can be conveyed using diacritical marks.
Although inputting characters using a Pinyin-based scheme is fairly accurate, the process is tedious, especially when used in conjunction with small soft-keyboards. The Pinyin representation of each character requires one to six keystrokes without tonal information; conveying tonal information adds another keystroke.
In order to decrease the number of keystrokes required for inputting Pinyin representations of Chinese characters, some desktop input methods, or IME""s, use a double-spelling scheme that divides a Pinyin representation into an initial sound and a final sound. These schemes typically map a standard English keyboard layout to a double-spelling layout and reduce the number of keystrokes involved in inputting each character to two or three. To use this scheme effectively, however, the user must learn and memorize the double-spelling layout. In addition, each key may be mapped to more than one initial or one final sound, and there is no standard mapping scheme. As a result, little significant advantage is realized over fully spelling out Pinyin representations. Further, existing double-spelling schemes are inadequate for use with handheld computing devices, which typically lack a physical keyboard.
While these approaches are suitable for use in desktop computing environments, they are unsuitable for use in hand-held computing environments, which by their nature cannot use large input devices, such as a PC keyboard. Indeed, hand-held computers typically use touch-sensitive screens and graphical user interfaces (GUIs) known as soft keyboards to receive input.
In this context, a soft keyboard is a graphical representation of a keyboard displayed on a touch sensitive screen. To input letters or other characters using a soft keyboard, the user touches the appropriate keys on the graphic keyboard with a stylus or other object. Because soft keyboards are limited to the size of the display screen and are therefore typically quite small, they cannot implement a large number of keys.
Handwriting recognition techniques have also been used to provide input to hand-held computers. This approach can be reasonably accurate for languages using the Roman alphabet due to the relatively simple nature of the constituent letters. For Chinese and other languages that do not use the Roman alphabet, however, this approach can suffer losses in both speed and accuracy. For example, in the Chinese language, many characters are somewhat complex and can require as many as twenty strokes to input. The number of strokes involved in inputting a character makes the process an inefficient one. In addition, imprecise strokes can cause the wrong character to be rendered. Further, some users only know how to pronounce characters and not how to write them. For these reasons, handwriting recognition has not adequately addressed the issue of inputting Chinese characters.
Using conventional input techniques, inputting Chinese characters continues to present a significant speed obstacle to computer processing. Accordingly, a need continues to exist for an accurate, efficient approach to inputting characters in languages not based on the Roman alphabet that is suitable for use with a hand-held computer.
According to various example implementations of the invention, there is provided a double-spelling soft keyboard that is used to input characters in a non-alphabetic language, such as Chinese, as described herein below. These characters are represented by a combination of an initial sound, a final sound, and/or a tone. In particular, the invention provides, among other things, for an initial soft keyboard that allows the user to select the initial sound, if present. Based on which initial sound is selected, a final soft keyboard offers the user a choice of final sounds that combine to form valid Pinyin representations of characters with the initial sound. Tone information may also be supplied by the user. After the initial sound, the final sound, and/or the tone have been input, i.e., after the complete Pinyin representation has been input, the desired character is predicted. This prediction can also be informed by contextual information, linguistic patterns, and the user""s previous input.
One particular implementation is directed to a method for inputting a desired character in a non-alphabetic language. First, the user is presented with a graphical representation of an initial soft keyboard having a plurality of first keys. At least some of the first keys represent initial sounds. The user is then presented with a graphical representation of a final soft keyboard having a plurality of second keys. At least some of the second keys represent final sounds. Each of the second keys assumes either an enabled state or a disabled state, depending on a user selection of one of the first keys. The desired character is determined at least in part as a function of a user selection of one of the first keys and one of the second keys. According to one example implementation, the desired character is determined further based on the user selection of a tone or space key. In still another particular implementation, the user selects the desired character from a candidate or homophone list that appears.
In another implementation, a user is presented with a graphical representation of an initial soft keyboard having a plurality of first keys. At least some of the first keys representing initial sounds. The user is then presented with a graphical representation of a final soft keyboard having a plurality of second keys. At least some of the second keys represent final sounds. Each of the second keys assumes an enabled state or a disabled state, depending on a user selection of one of the first keys. A string is constructed at least in part as a function of a user selection of the first and second keys. A statistical language model is used to determine the desired character at least in part as a function of the string.
Other implementations are directed to computer arrangements and computer-readable media for implementing these methods.
Still another implementation is directed to a handheld computing device having a touch-sensitive screen and configured to receive input of a desired character in a non-alphabetic language by displaying on the touch-sensitive screen a graphical representation of an initial soft keyboard having a plurality of first keys. At least some of the first keys represent initial sounds. The handheld computing device receives a user selection of one of the first keys using the touch-sensitive screen. It then displays on the touch-sensitive screen a graphical representation of a final soft keyboard having a plurality of second keys. At least some of the second keys represent final sounds. Each of the second keys assumes an enabled state or a disabled state, depending on a user selection of one of the first keys. The handheld computing device receives a user selection of one of the second keys using the touch-sensitive screen. It then determines the desired character at least in part as a function of a user selection of one of the first keys and one of the second keys. In one example implementation, the desired character is determined further based on the user selection of a tone or space key. In another particular implementation, the user selects the desired character from a candidate or homophone list that appears. In still another example implementation, a string is constructed at least in part as a function of a user selection of the first and second keys. A statistical language model is used to determine the desired character at least in part as a function of the string, e.g., among candidates that correspond to the Pinyin string.
The above summary of the present invention is not intended to describe every implementation of the present invention. The figures and the detailed description that follow more particularly exemplify these implementations.